As an outspoken lover of hardtails myself, I hear you on that. But Nearly any full suspension bike (all things equal) will be much more forgiving on not just your back, but also it insulates your whole body.
This was never more clear to me than when doing a 6 hour solo on chunky terrain, or a 24 hour event on chunky terrain. On a hardtail I was pretty shot by the end, but even a short travel XC full suspension was leagues more comfortable, and by the end I still felt fresh, not whole body tired like before. All you have to do is sit there and pedal. So easy.
My opinion:
I don't think you need a long travel bike to be more comfortable, nearly any Trail bike with 120-150mm of rear travel will work equally well and be more efficient pedaling. Which brings me to the E-bike. Sounds like you are a perfect candidate for a full suspension E-bike. I admit I'm not a fan personally, and they're illegal here largely, but frankly I would have zero problems with someone in your situation riding an E-bike.
What's the budget? I ask because a good aluminum FS bike can be had for $2.5-3k, but an E-bike will be twice that.
This was never more clear to me than when doing a 6 hour solo on chunky terrain, or a 24 hour event on chunky terrain. On a hardtail I was pretty shot by the end, but even a short travel XC full suspension was leagues more comfortable, and by the end I still felt fresh, not whole body tired like before. All you have to do is sit there and pedal. So easy.
My opinion:
I don't think you need a long travel bike to be more comfortable, nearly any Trail bike with 120-150mm of rear travel will work equally well and be more efficient pedaling. Which brings me to the E-bike. Sounds like you are a perfect candidate for a full suspension E-bike. I admit I'm not a fan personally, and they're illegal here largely, but frankly I would have zero problems with someone in your situation riding an E-bike.
What's the budget? I ask because a good aluminum FS bike can be had for $2.5-3k, but an E-bike will be twice that.